1. Field of the Invention
The invention is related to the field of communications and, in particular, to systems and methods for measuring per call data for calls in IMS networks.
2. Statement of the Problem
In code division multiple access (CDMA) networks, Per Call Measurement Data (PCMD) servers collect call measurement data on mobile voice and data calls in the network. The collected data includes call details, resource usage, and call failure information. The PCMD server collects data for incomplete calls, such as denied calls and setup failures. The call measurement data collected by the PCMD server may be analyzed by tools or post-processing systems for performance reporting, i.e., call disposition summaries, release cause codes, error codes, etc. The PCMD server provides a more flexible and scalable method of reporting system performance information than is possible with only cumulative counts that cannot be related to individual calls. With cumulative count reporting, the operator will have cumulative counts of call measurement data regarding network performance, but will not be able to view or process call measurement data on a per call basis. The disadvantage with cumulative counts is that important call measurement data may need to be categorized on a per call basis to determine network problems, and the ability to categorize data on a per call basis is not available with cumulative counts.
One type of communication network gaining popularity is an IP Multimedia Subsystem (IMS) network. As set forth in the 3rd Generation Partnership Project (3GPP), IMS provides a common core network having access-agnostic network architecture for converged networks. Service providers are accepting this architecture in next generation network evolution. The IMS architecture is initially defined by the 3GPP to provide multimedia services to mobile subscribers over an Internet Protocol (IP) network. IP networks have become the most cost savings bearer network to transmit video, voice, and data. IMS uses the advantage of IP networks to provide multimedia services for IMS subscribers on an IMS platform. The signaling used within IMS networks is Session Initiation Protocol (SIP). IMS defines the standard SIP interface between application servers, the IMS core network (CSCF), the IMS subscriber, the IMS database (HSS), and IMS billing elements. These standards can reduce the network integration costs and let the subscriber enjoy more stable services.
One problem with the present 3GPP IMS standards is that the standards do not define Per Call Measurement Data (PCMD). IMS networks have a different architecture and configuration from legacy networks, such as CDMA, and there are no centralized switching entities, such as a Mobile Switching Center (MSC), in the IMS network to collect per call measurement data. Unfortunately, the current architecture does not provide implementation of the PCMD functionality.